Please note that the text in this document summarizes the Record of Decision for the purposes of facilitating searching and retrieving key text on the ROD. It is not the officially approved abstract drafted by EPA Regional offices. Once EPA Headquarters receives the official abstract, this text will be replaced.

The 50-acre South Andover Salvage Yards Superfund site is located in Anoka County, Minnesota, approximately 16 miles north-northwest of Minneapolis and 3 miles northeast of the City of Anoka. The site is comprised of several privately owned parcels of land, which jointly encompass more than 50 acres. Bunker Lake Boulevard defines the northern extent of the site. The eastern site boundary is roughly 500 feet west of Jay Street.

EPA issued a ROD on December 24, 1991 which documented a decision for remedial action of soil. The major components of the selected remedy included: excavate and treat approximately 2,100 cubic yards of carcinogenic polyaromatic hydrocarbons (CPAH) contaminated soils using an above-ground biological treatment unit; excavate and transport approximately 9,300 cubic yards of soils contaminated with PCBs, CPAHs, lead and antimony to an off-site industrial and/or commercial permitted landfill; and sample and remove drums which were inventoried by MPCA and EPA. During Remedial Design/Remedial Action (RD/RA) negotiations and as a result of a Pre-Design Study, additional soil samples were taken to refine the volume of contaminated soil. The first round of soil sampling occurred in October 1992, the second was in July 1993. Both sampling events used a grid system which placed sample points approximately 10 to 30 feet away from each other. The July 1991 RI used a grid system which placed sample points approximately 75 to 100 feet away from each other. Results from the October 1992 and July 1993 sampling events have shown that the CPAH contaminated soil volumes originally estimated in the July 1991 RI, were significantly less. The original volume of CPAH contaminated soils was estimated at 2,100 cubic yards. Data from the more recent sampling events indicate the volume to be approximately 250 cubic yards. As a result, EPA and MPCA are amending their December 1991 decision concerning contaminated soil at the site. Specifically that portion of the remedy which addresses CPAH contaminated soil from hot spots 1, 5, and 6 will be amended to reflect off-site thermal treatment as opposed to on-site biological treatment. The original cleanup standards for the various soil contaminants, however, would not change. On February 5, 1993, the PEPS referred to as the South Andover Administrative Group (SAAG), entered into a Consent Decree with EPA. This Consent Decree was lodged with a federal court on April 30, 1993 and was later entered into the same court on August 27, 1993. As part of this Consent Decree, the SAAG agreed to perform the necessary studies and activities required to remediate the South Andover Salvage Yards.

EPA and the MPCA are amending this decision so that the predominantly CPAH-contaminated soils would betaken off-site for thermal treatment in either a rotary kiln incinerator or a low temperature thermal desorption unit. Additionally, this amendment serves to update the Maximum Contaminant Levels (MCLs) for several constituents that are currently being monitored in groundwater.

The remedy status for the media addressed in this ROD are as follows: Soil 1 is Final Action. The media associated with this site has a volume of 250 Sq. Miles. The state concurs with the selected remedy.

Remedy:

EPA and MPCA are amending the original soil remedy by replacing on-site biological treatment with off-site thermal treatment of CPAH-contaminated soil. The amended remedy includes, excavating and transporting approximately 250 cubic yds of CPAH-contaminated soil from areas 1, 5, and 6 to a permitted off-site facility, treating the material using either rotary kiln incineration or low-temperature thermal desorption, collecting and treating ash and exhaust gases, as necessary, treating the carrier gas stream further with an afterburner or cooling in stages to condense the volatilized water and organics into liquids, followed by carbon filtration. The portion of the remedy that addresses the contaminated soils in areas 2, 3, 4, and 7 will remain the same. Soils from these areas will be excavated and transported to an off-site industrial and/or commercial permitted landfill. Lastly, since site-specific groundwater parameters were affected when EPA updated the MCLs in 1993, this amendment also updates the MCLs for the various groundwater monitoring parameters. The overall Not Documented costs are $60,000 to $67,000.

Text:

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